Up to now two rubber sealings have been used to seal the connection between the nacelle and the tower in order to avoid that grease from the yaw system is running down the tower. Furthermore, the sealing is used to keep a closed environment in the nacelle. The rubber sealing consists of one circular rubber sealing mounted on the top of the tower and one part mounted on the nacelle respectively (see FIG. 2).
The nacelle is installed on top of the tower by lifting and lowering the nacelle down on to the tower. However, the rubber sealings need to be heeled over each other in order to get the right order of the rubber sealings. This task is time consuming as the turbine needs to be yawed whereby and the rubber sealing is heeled each other similar to when removing a tire from a wheel rim. Furthermore, yawing of the turbine is not possible before the turbine is connected to the grid and it could easily take a couple of days before the installation of the tower sealing can be completed.
The sealing prevents grease from running down the tower but is doesn't keep track of the grease inside the nacelle.